Analysis of Four Categories of Laser Cutting

Laser cutting uses a high power density laser beam to irradiate the material to be cut, so that the material is quickly heated to the vaporization temperature and evaporated to form a hole. As the beam moves to the material, the hole is continuously formed with a narrow width (such as 0.1mm) , To complete the cutting of the material. Laser cutting can be divided into four categories: brightest laser pointer vaporization cutting, laser melting cutting, laser oxygen cutting and laser scribing and controlling fracture.

Laser vaporization cutting: the use of high-energy laser beam heating the workpiece, the temperature rose rapidly in a very short period of time to reach the boiling point of the material, the material began to vaporize, the formation of steam. These vapors are ejected at high velocities, forming a cut in the material while the vapors are ejected. The vaporization heat of the material is generally large, so a large amount of power and power density is required for burning laser pointer vaporization cutting. Laser vaporization cutting for thin metal materials and non-metallic materials (such as paper, cloth, wood, plastic and rubber, etc.) cutting.

Laser melting cutting: laser melting to melt the metal material, and then through the nozzle coaxial with the beam blowing non-oxidizing gases (Ar, He, N, etc.), relying on the strong pressure of gas to liquid metal discharge, Forming a cut. Laser melting does not require the metal to fully vaporize, the energy required is only vapor cutting 1 / Laser melting cutting is mainly used for some difficult to oxidize the material or active metal cutting, such as stainless steel, titanium, aluminum and its alloys.

Laser oxygen cutting: The principle of high power laser pointer oxygen cutting is similar to oxyacetylene cutting. It uses laser as a preheating heat source, with oxygen and other reactive gases as cutting gas. On the other hand, the molten oxide and the molten material are blown out from the reaction zone to form a notch in the metal. In this way, the gas is oxidized and the oxidation heat is released. As the oxidation process in the cutting process produces a lot of heat, so the laser oxygen cutting the energy required is only melt cutting 1/2, and cutting speed is much larger than the laser vaporization cutting and melting cutting. Laser oxygen cutting is mainly used for carbon steel, titanium steel and heat-treated steel and other easily oxidized metal materials.

Laser scribing and control of fracture: laser scribing is the use of high energy density laser scanning of the surface of brittle materials, the material heated to evaporate a small tank, and then impose a certain pressure, brittle material will crack along the small slot . Lasers for laser scribing are typically Q-switched lasers and CO2 lasers. The controlled fracture is a steep temperature distribution created by the use of a 1000mw laser pointer scribe, creating localized thermal stresses in the brittle material and breaking the material along the trough.